Spontaneouse generation is the idea that living organisms can be spontaneously formed from non-living substances.[1] Other definitions refer to it as to the concept that animal forms are created by the decay of organic matter[2][3]. Common theories included:

Moldy grain produces mice

Rotten meat produces maggots

Rotting garbage produces rats

Experiments in the 1600s through the 1800s discredited this idea. These experiments took the form of allowing meat to rot in sealed and semi-sealed containers (Francesco Redi, 1668), which demonstrated that maggots only formed in meat that flies laid eggs in; and by storing sterilized soup in bottles that prevented dust and bacteria from entering (Louis Pasteur, 1860).